The goal of this project is to establish a multi-user facility at Rush Medical College that will allow non-destructive, three-dimensional measurement of bone architecture through the use of x-ray micro computed tomography. This facility is designed to meet the needs of multiple investigators who are supported by funded NIH grants and who needs the capabilities of the requested instrument in order to further the specific aims of their ongoing research. The approaches made possible in this facility will significantly extend their work beyond that which can be accomplished using techniques currently available. Extensive financial support is being provided by Rush Medical College as evidenced by a cost-sharing arrangement which includes a total of $327,558 for dedicated laboratory space and partial operating costs for a period of 5 years. This facility will initially support the specific aims of six separate NIH- funded groups. These projects are being conducted on the general topic of skeletal injury and repair, encompassing joint replacement, osteoarthritis, rheumatoid arthritis and tissue engineering. The investigations use animal models and human autopsy material. In many of the studies, bone architecture is an important endpoint. The methods currently used by the investigators, although state-of-the-art, allow only two-dimensional analyses and, in many cases, are destructive. We anticipate being able to combine very sophisticated three-dimensional characterization of the bone architecture (at a 10 mum X 10 muM X 10 muM resolution) in the same specimens in which molecular biology approaches to assess gene expression are used. Furthermore, the three- dimensional bone architecture data can be used as the basis for mechanical analyses with finite element models. Thus, the anatomy, mechanical behavior and molecular biology of the same sample can now be studied in conjunction. The new facility will also greatly enhance the research training of students, research residents and post-doctoral fellows. Consequently, the facility is expected to make a major contribution to the research and teaching missions of Rush Medical College.